Polyalkylene imines, particularly polyethylene imine are known to have utility as flocculants and for water treatment; generally as the free bases or in salt form. Although their performance is rather dosage sensitive, these materials are effective in water clarification operation. However, when used in the treatment, e.g. dewatering, of some industrial and municipal sludges the performance of polyethylene imines has been unsatisfactory.
Accordingly there is a need for polymers that are suitable to effect better sludge dewatering by reduced resistance to filtration in water treatment operations.